The present invention concerns a transfer conveyor system for use between a sterile or "clean" room and a relatively non-sterile room in a sterile product packaging system. In one specific aspect, the invention concerns a transfer conveyor system for conveying bottles from a filling/stoppering machine in a sterile room to a capping machine in a non-sterile room, while minimizing the potential for cross contamination caused by the transfer conveyor system.
Most modern packaging systems are mechanized with electrically controlled conveyors used to transfer containers between packaging stations. For example, controlled conveyors transfer containers to a station in which the containers are filled and from there to a separate station in which the containers are closed, after which the container is discharged. Bottle containers are particularly well suited for this mechanized approach to filling and closing. In some industries, it is essential that certain of the packaging operations occur in a sterile or "clean" environment. One such field concerns medicines or drugs which are subject to regulation by the Food and Drug Administration. In this industry, the filling/stoppering operation is typically conducted in a sterile room to avoid contamination of medicine or drug. Other steps of the packaging process, such as closing the container, need not occur in the sterile environment.
Referring now to FIG. 1, a diagramatic view of a sterile product filling and bottle capping system 10 is depicted to illustrate one such typical system in the industry. For such a system 10, an input conveyor 11 continuously provides containers, such as bottles, to a filling/stoppering machine 12. The filling/stoppering machine resides within a sterile room 13. Alternatively, the source of bottles may also reside within the sterile room 13. At the filling/stoppering machine 12, the empty and sterilized bottles are filled with a medicine or drug and then stoppered. The newly filled and stoppered containers are passed by way of a transfer conveyor 14 to a capping machine 15. As illustrated, the capping machine 15 is housed within a relatively non-sterile room. The capping machine 15 engages a closure to the newly filled bottles and passes the final product to a discharge conveyor 17.
In many prior systems, such as the system 10, the transfer conveyor 14 includes a continuous belt-type conveyor that extends between time filling/stoppering machine 12 and the capping machine 15. One significant drawback of using a continuous belt conveyor is that the belt passes from the sterile to time non-sterile environment and then returns to the sterile room, presenting a significant risk of a contaminated belt returning into the sterile room. Thus, the use of a belt conveyor as time transfer conveyor 14 between sterile and non-sterile rooms may substantially defeat the purpose of segregating time two environments.
Another approach in time industry has been to perform all of the packaging operations in a sterile environment. Thus, the filling/stoppering machine and capping machine would both be situated within the sterile room. In this arrangement, only the final product leaves the sterile room, thereby significantly eliminating the risk of contamination of the medicine or drugs contained therein. Although this approach may provide the greatest security against contamination, large sterile environments are difficult and expensive to maintain. Housing all of the packaging machinery in a sterile environment increases the size of the room required to house all the equipment, which likewise increases the requirements for the sterilization system.
What is needed in the industry is a sterile product packaging system which provides time greatest security against contamination of the product, such as medicines or drugs, without incurring the expense of an enlarged clean room. In addition, this system would optimize the requirements of maintaining a sterile room so that only the essential step of filling the container with sterile product and stoppering need be performed in a sterile environment, leaving the remaining steps of the packaging system to be conducted in non-sterile environments.